Anion-cation complexes with surfactant properties, which are essentially independent of the pH, are described in the U.S. Pat. No. 4,093,642. These complexes contain at least one organosilicon compound, which is defined as siloxane A or B.
The siloxane A has the structural formula ##STR1## wherein R is a univalent hydrocarbon group with 1 to 18 carbon atoms,
R' is a divalent organic group with 1 to 18 carbon atoms, PA1 XX.sup.- is a divalent anionic group, which is linked covalently to R' and ionically to Y.sup.+, PA1 Y.sup.+ is a univalent cation, which has at least 8 carbon atoms and is derived from a cationic surfactant with a halogen counterion by removal of the halogen and which is free of ionically bound hydrogen, PA1 m is a whole number with a value of 1 to 100, PA1 n is a whole number with a value of 0 to 200 and the ratio m/(n+2) amounts to 0.1 to 20. PA1 R' is a divalent organic group with 1 to 18 carbon atoms, PA1 YY.sup.+ is a divalent cationic group, which is bound covalently to R' and ionically to X.sup.- and is free of ionically bound hydrogen, PA1 X.sup.- is a univalent anion, which has at least 8 carbon atoms and is derived from an anionic surfactant with a univalent metal counterion by removal of the metal, PA1 m is a whole number with a value of 1 to 100, PA1 n is a whole number with a value of 0 to 200 and the ratio m/(n+2) amounts to 0.1 to 20. PA1 R.sup.1 within the molecule is the same or different and can be PA1 R.sup.3 has the same meaning as the R.sup.2 group or is an epoxide group linked over a carbon atom to silicon, with the proviso that, in the average molecule, at least one R.sup.3 group is an epoxide group, PA1 a has a value of 0 to 500, and PA1 b has a value of 0 to 5.
The siloxane B has the structural formula ##STR2## wherein R is a univalent hydrocarbon group with 1 to 18 carbon atoms,
Pursuant to this U.S. Pat. No. 4,093,642, the surface active anion-cation complex is synthesized by first synthesizing the anionic surfactant and the cationic surfactant separately and then mixing equimolar amounts of the two surfactants in a solvent such as water or alcohol and, optionally after removal of the solvent, separating the product from the precipitated salt.
For the case in which the two surfactant components are organosilicon compounds, this reaction can be described as follows. ##STR3##
Instead of a silicone surfactant, an organic surfactant can also be selected.
The surfactant complexes have a high surface activity and can be used in manifold ways. It is, however, a disadvantage that, according to this state of the art, it is necessary to employ a 2-step method and to remove a considerable salt load. The method is also unsuitable for synthesizing longer chain and polyfunctional silicone sulfonates and their cation complexes.
The present invention is therefore concerned, in particular, with the simplification of the preparation of such complexes, with the aim of achieving a 1-step method, which can also be employed for longer chain and polyfunctional siloxanes.